In central Florida heat pumps seem to be the most widely used method of residential air conditioning. In our area heat strips generally will run simultaneous with compressor loads on defrost cycle and during coldest of conditions. This being true, 220.30 (C)(2) applies to calculations--taking both compressor and heat strip loads at 100%. My question is--on an existing dwelling unit a pool heat pump is added. For purposes of verifying adequacy of service size must heat strip and compressor load be taken at 100% as in 220.30 (C)(2) or are these loads taken at 40% as appliance loads per 220.31(A)? (no additional AIR condition or SPACE HEATING is being added) The numbers are so close that the answer means the difference between the existing service working or having to upgrade.
[ January 08, 2004, 07:45 AM: Message edited by: ajohnson ]
[ January 08, 2004, 07:45 AM: Message edited by: ajohnson ]